title: Community-acquired urinary tract infection: age and gender-dependent etiology.
abstract: BACKGROUND
  Choosing the antimicrobial agent for initial therapy of urinary tract infection (UTI) is usually empirical and should consider the prevalence of uropathogens in different age groups and gender.
  
  
  OBJECTIVE
  To establish prevalence rates of uropathogens in community-acquired UTI in relation to age and gender.
  
  
  METHODS
  Cross-sectional study conducted in the emergency department (ED) of a general hospital, from January to December, 2010, in patients younger than 15 years old who had clinical suspicion of UTI and collected quantitative urine culture. UTI was defined as urine culture with growth of a single agent > 100.000 colony forming units (cfu)/mL in a midstream collection or ≥ 50.000 cfu/mL in urethral catheterization.
  
  
  RESULTS
  There were 63.464 visits to ED. 2577 urine cultures were obtained, of whom 291 were positive for UTI (prevalence = 11.3% of clinical suspicion and 0.46% of visits), 212 cases (72.8%) in females, median age = 2.6 years. The predominant uropathogen was E. coli (76.6%), followed by Proteus mirabilis (10.3%) and Staphylococcus saprophyticus (4.1%). Among infants < 3 months, prevalence rates of E. coli were significantly lower (50% vs 78.4%; OR = 0.276; p = 0.006). Higher prevalences of Staphylococcus saprophyticus occurred among patients > 10 years (24.4% vs 0.4%; OR = 79.265; p < 0.0001). Proteus mirabilis was significantly more prevalent in boys than girls (24.0% vs 5.2%; OR = 5.786; p < 0.001).
  
  
  CONCLUSIONS
  E. coli was the most prevalent community-acquired uropathogen. Nevertheless, initial empiric antimicrobial treatment of UTI should consider the significant prevalence of other agents different from E. coli in infants < 3 months, the high prevalence of Staphylococcus saprophyticus in patients > 10 years and Proteus mirabilis in males.
authors.affiliation: Teaching Hospital of the University of São Paulo, Brazil.
authors.forename: Denise Swei
authors.initials: DS
authors.lastname: Lo
authors.forename: Huei Hsin
authors.initials: HH
authors.lastname: Shieh
authors.forename: Selma Lopes Betta
authors.initials: SL
authors.lastname: Ragazzi
authors.forename: Vera Hermina Kalika
authors.initials: VH
authors.lastname: Koch
authors.forename: Marina Baquerizo
authors.initials: MB
authors.lastname: Martinez
authors.forename: Alfredo Elias
authors.initials: AE
authors.lastname: Gilio
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000367:Age Factors; D001424:Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D017678:Sex Distribution; D012737:Sex Factors; D014552:Urinary Tract Infections / Q000453:epidemiology* / Q000382:microbiology